Dissipation of Oscillation Energy of Hemispherical Resonator in Attachment Area

Mass defect (unbalance) of a hemispherical resonator creates forces and moments affecting its center of mass and making the resonator stem oscillate. A part of oscillation energy is dissipated in vicinity of the resonator attachment, which reduces its Q-factor and leads to additional systematic drift. The paper considers the main factors determining the dissipative characteristics of the resonator-base joint such as the resonator design and dimensions, internal friction in the bonding layer, and the defects of this layer. It has been shown that the internal friction due to attachment is proportional to the layer thickness and inversely proportional to the thickness of base, stem diameter, and Young’s modulus of the layer material. Asymmetric stem fixation in the hole in base, ovality of hole or of the stem, bubbles in the bonding layer result in azimuth-depending losses and additional HRG systematic drift.